This paper studied the real-time performance of three-tier client/server architecture used in remote monitoring system. A scheduling algorithm was adopted in middleware of this architecture, which based on the regulation: setting the priority of task according to the percentage of useful data in the data-buffer or the LAD (most locally available data first) but not according to the earliest deadline. Contrast simulation of the improved algorithm and EDF (earliest deadline first algorithm) had been achieved from program developed using VC++ at different average task lengths and update workloads under the tentative parameters such as the size of data in different data-buffer, the time used for fetch an object from these data-buffers and average task inter-arrival time. The results showed that the LAD’s completed task percentage before deadlines was higher than EDF, which proved LAD was more suitable to improve the real-time performance of three-tier client/server architecture.
